JPH05230377A - Curable polysiloxane composition containing filler - Google Patents

Abstract

PURPOSE: To improve the rheology of a curable filled polysiloxane composition for sealant.

CONSTITUTION: The curable composition containing a hydroxypolysiloxane, a silane curing agent, a fine filler (e.g. calcium carbonate), a catalyst, and a polymer having at least one carboxylic acid anhydride group on the polymer chain as a rheclogical additive (e.g. polybutadiene treated with maleic anhydride).

COPYRIGHT: (C)1993,JPO

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to curable filled polysiloxane compositions. Curable polysiloxane compositions are used in a variety of applications, such as sealant compositions, which are applied at the joints between elements to provide a resilient seal. Such compositions, which cure at room temperature upon exposure to atmospheric moisture, generally do not require special heating or other conditions to obtain a desired quality seal, such as sealing highway connections. It is particularly attractive for use as a sealant in joints in parts such as automobile headlights and joints in glass applications.

[0002]

BACKGROUND OF THE INVENTION Compositions intended for use as sealant compositions are required to have combinatorial properties. For example, the composition may be cured at ambient or elevated temperatures at an acceptable rate to provide a cured product that adheres at least slowly to the surface of the joint, where the cured product is at 100% elongation. It must have the desired resiliency properties as expressed by modulus, elongation at break and tensile strength. The effectiveness of the seal at the chosen location depends, in principle, on the good adhesion and elastic properties of the seal to the joint surface.

The adhesive and elastic properties of the seal are governed, at least in part, by the formulation of the sealant composition and are influenced by the type and proportion of filler and elastomer used. Fillers often used in room temperature curable silicone sealants are generally small particle size so-called reinforcing fillers such as precipitated and fused silica, and so-called non-reinforcing fillers such as clay, ground glass,
Quartz and milled oxides, hydroxides, carbonates and bicarbonates such as calcium, magnesium, barium or zinc produced by milling or precipitation techniques.
The carbonate may be treated, for example a stearate coated surface, or untreated. Of these materials, silica is usually actually used. Calcium carbonate is also used, but surface-treated one is preferable. It has been found that the adhesion of the composition to the substrate is influenced by the filler used in the composition.

European Patent No. 384609 describes 100 parts by weight of (A) hydroxypolysiloxane;
Formula: R _{a R'b} Si silane or unit: R _{a R'b} SiO
Curing agent 5-1 consisting of siloxane having _{(4- (a + c)) / 2}
A product formed by mixing with 2 parts by weight [in the above formula, each R represents a monovalent hydrocarbon residue, and each R'is hydroxy,
Represents an alkoxy or alkoxyalkoxy group, a + b
= 4, a is 0 or 1, b is 3 or 4, c is 1, 2 or 3, and a + c is 3 or less], (B) of calcium carbonate mainly composed of particles having a surface area of 10 m ² / g. Mixture of 10 to 80% by weight of mixture and calcium carbonate consisting mainly of particles having a surface area of 0.5 to 12 m ² / g 2
50-20 fillers containing a mixture with 0-90% by weight
Curable compositions containing 0 parts by weight, and (C) a catalytic amount of a titanium or tin compound that accelerates curing of the product in the presence of atmospheric moisture are described.

The compositions described in said European patent are described as having the desired balance of rubber elasticity and adhesion. However, some of the compositions described above which, when cured, have desirable modulus properties as a sealant tend to exhibit faster flowability than that desired as a sealant for vertically long joints before cure. .. For example, when large amounts of non-reinforcing fillers are used, the composition tends to flow fast, is often uncontrollable when extruded, and continues to flow until cured, so the composition is suitable for vertical joints. Not suitable as a sealant. Increasing the proportion of reinforcing filler to compensate for this rheological effect increases the modulus of the cured sealant. The presence of a strong reinforcing filler in a sufficient proportion to provide the desired flowability, for example fused silica (which should be used in a relatively small proportion) or precipitated calcium carbonate (which is similar to silica) Higher amounts should be used to obtain a rheology of 10) is desirable for many sealant applications.
Tends to lead to a cured sealant with a modulus higher than 0% elongation modulus.

In the silicone sealant art, plasticizers such as non-reactive silicone liquids or gums such as trialkylsilyl polydiorganosiloxanes, or organic diluents such as aromatic petroleum hydrocarbons.
It is known to reduce the modulus of cured compositions using, for example, petroleum-based naphtha or polyethers. However, the presence of a large amount of plasticizer to lower the modulus increases the flowability of the composition and thus leads to poor rheology. In addition, the formula: RSO ₃ H (however,
R represents a hydrocarbon residue which may be halogenated and contains an aliphatic chain of up to 20 carbon atoms) sulfonates, eg alkyl or alkylaryl sulfonic acids, eg dodecylbenzene sulfone It has also been proposed to add an acid (DBSA) as a modulus lowering agent to a silicone-based sealant composition. Although the reducer has a large effect on modulus, it alone has a very limited effect on the rheology of flowability required.

[0007]

Surprisingly, not only is excellent modulus and adhesion desirable, but also desirable flowability for extrusion of the composition at acceptable flow rates upon contact of the joint surfaces. A calcium-carbonate-filled silicone-based composition having at least one carboxylic acid anhydride group in or on the polymer chain, the composition having no sagging, and capable of withstanding degradation during curing of the composition. It has been found to be provided by incorporating a polymer of

The present invention provides a hydroxypolysiloxane with at least one silane or siloxane curing agent, finely divided filler, a catalyst that accelerates the curing of the product in the presence of atmospheric moisture, and at least one in or on the polymer chain. Rheological additives containing polymers with carboxylic acid anhydride groups (rheological
The present invention provides a curable composition containing a product formed by mixing with an additive).

The hydroxypolysiloxane used in the composition of the present invention can be linear or branched, and can have a functionality of two or more. The polymer may contain a branching unit of the formula: R _a SiO _{(4-a) / 2} , where R represents a monovalent hydrocarbon residue and a is a value of 0 or 1. Most preferred is α-ω dihydroxypolysiloxane, which has the general formula: HO (R ₂ SiO) _x H [R
May be represented by a monovalent hydrocarbon residue, for example an alkyl group having up to 12 carbon atoms (eg methyl, ethyl, propyl, vinyl or allyl) or an aromatic group (eg phenyl)]. A preferred material is the formula: HO (R ₂ SiO) _x H [where x is, for example, 2
Viscosity at 5 ℃ 50 ~ 500,000mm ² / s, preferably 1
Is an integer such that it is a polymer in the range of 0,000 to 100,000 mm ² / s], a hydroxy-terminated polydiorganosiloxane. These materials are usually made by adding diorganodi-chlorosilane to a water / solvent mixture to obtain a mixture of low molecular weight hydroxy endblock oligomer and cyclic siloxane in the solvent. Linear α of desired molecular weight
-Ω dihydroxy polysiloxane polymer, by the method of condensation or equilibration in the presence of a basic or acidic catalyst,
It can be prepared from low molecular weight linear dihydroxypolydiorganosiloxanes (prepared as described above or by the method of ring opening of the above-mentioned cyclic substances). In preferred materials, at least 85%, and preferably all, of R are methyl groups.

The hydroxypolysiloxane polymer can be incorporated into the curable composition by mixing it with a silane or siloxane curing agent. In the compositions of the present invention, a compound containing three or more silicon-bonded groups that is or becomes reactive (eg, under the influence of atmospheric moisture) with the silicon-bonded hydroxyl groups of the polysiloxane, and the hydroxypolysiloxane. In order to form a mixture and / or reaction product with, the curing agent is a silane of the formula: R _b R ′ _c Si, or a unit: R _a R ′ _d SiO _{(4- (a + d)) / 2} . It may be a siloxane having [wherein R represents a monovalent hydrocarbon residue, R'is hydroxy, alkoxy, alkoxyalkoxy group, alkenylalkoxy or oximo (oxim).
o), b + c = 4, b is a value of 0 or 1, c
Is a value of 3 or 4, a is a value of 0, 1 or 2, d is a value of 1, 2 or 3, and a + d is 3 or less]. Curing agents which can be used are, for example, the known trifunctional and tetrafunctional steam-activated crosslinkers, such as alkoxy, alkoxyalkoxy or oximo-substituted silanes [eg methyltrimethoxysilane, phenyltrimethoxysilane]. ,
Methyl tris (methyl ethyl ketoximino) silane) and methoxymethyl bis (methyl ethyl ketoximino)
Silane] is used. The compositions of the present invention may also contain a polydiorganosiloxane of the general formula shown below, for example as described in US Pat. No. 4,898,910.

[0011]

[Chemical 1] [In the above formula, R has the same meaning as above, and R ¹ is the formula:

[0012]

[Chemical 2] (However, n is a value of 2 or 3, and m is a value of 0 or 1.). ]

The composition of the present invention contains a finely divided filler. Preferred fillers are commercially available precipitated or ground calcium carbonate, which may contain, for example, small amounts, for example magnesium carbonate, and mixtures thereof. The surface of these fillers may be treated with stearic acid. Preferred fillers are those containing about 0.4 to 3.0% by weight stearate. The commercially available precipitated calcium carbonate is generally crystalline and has a substantially uniform particle size with a surface area of the order of about 20 m ² / g, but the commonly used commercially available mills. Calcium carbonate has a fairly widely distributed particle size, although other particle sizes may be used, and about 1
It is a crystalline or amorphous substance mainly composed of particles having a surface area of about ² m ² / g. Calcium carbonate mainly composed of particles having a surface area of 10 to 30 m ² / g 1
It is preferred to use a mixture of 0 to 80% by weight and 20 to 90% by weight of calcium carbonate which is mainly composed of particles having a surface area of 0.5 to 12 m ² / g. 10-30m ²
using a precipitated filler to provide a calcium carbonate having a surface area of / g, a ground filler to provide a calcium carbonate mainly composed of particles having a surface area of 0.5-12 m ² / g Is preferably used. The filler consisting of the calcium carbonate mixture is preferably present in the range of 100 to 250 parts by weight per 100 parts by weight of hydroxypolysiloxane. Compositions in which a large proportion of precipitated calcium carbonate is used tend to have poorer flowability than compositions in which a large proportion of coarsely ground calcium carbonate is used. Precipitated calcium carbonate comprises at least 10% by weight of the mixed filler, preferably at least 20% by weight.
It is preferable to use 0% by weight or less, preferably about 60 to 70% by weight or less. Ground calcium carbonate can be used in a proportion of 20 to 90% by weight of the mixed filler, and at least 60% by weight can be prepared.

The above calcium carbonate filler is preferably used as the sole filler. Additional fillers such as ferric oxide, diatomaceous earth, alumina, hydrated alumina, titanium oxide, gallal microballoons, organic fillers or resins,
Fractured quartz, calcium sulphate, calcium, magnesium, barium or zinc hydroxide, carbonate or bicarbonate, barium sulphate, and fused silica, or mixtures thereof can be included, but with the desired proportions reversed. Care must be taken not to affect the

The catalysts that can be used in the compositions of the present invention to promote the crosslinking of the hydroxypolysiloxane include the known tin and titanium compound catalysts. Suitable tin compounds are the tin salts of carboxylic acids, especially the commonly used stannous carboxylic acid salts. Examples of suitable catalysts are dibutyltin dilaurate, stannous acetate, stannous naphthenate, stannous benzoate, stannous sebacate, stannous succinate and stannous octoate. Suitable titanium compounds include alkyl titanates and alkyl titanium complex compounds such as tetraisobutyl titanate, tetraisopropyl titanate and di (isopropyl) -di (ethylacetoacetate) titanate.

The composition of the present invention comprises at least one polymer chain.
It contains a flowable additive containing a polymer with one carboxylic anhydride group attached. Without wishing to be bound by any particular theory, it is believed that the polymer interacts with the filler to affect the flow properties associated with the filler through chemical reactions or hydrogen bonding. The polymer can have 2 or more acid anhydride groups per polymer chain, with mixtures having an average of about 1 to 7 acid anhydride groups per polymer chain being preferred. The polymer selected is fluid or can be effectively fluid, for example by dissolving in an organic solvent at the temperature at which the composition is prepared. Preferred polymers are those that are liquid at room temperature, especially from 1,000 to 30,000 mm ² / s
It has a viscosity in the range of. Any desired polymer chain that does not adversely affect the properties of the composition can be used. Polymers having acid anhydride groups at the ends, in the chain or as pendants can also be used. The polymer used should be compatible with the many components in the composition so that it will not separate from the composition after it has been cured. Polymers made from polybutadiene or polystyrene are suitable for use in the present invention, as are polymers made from polysiloxane, at a rate of less than 10 parts by weight per 100 parts by weight of hydroxypolysiloxane. Polymers made by "functionalizing" polybutadiene with maleic anhydride or by copolymerizing styrene with maleic anhydride are commercially available and suitable for use in the present invention. There is. Treated with carboxylic anhydride, molecular weight in the range 1,000-6,000, 1,500
It is preferable to use a polybutadiene polymer having a viscosity in the range of up to 20,000 mm ² / s, an acid value in the range of 50 to 200 (mg KOH / g), and an average of 1.2 to 5 acid anhydride groups per molecule. .. This preferred polymer is preferably used in a proportion of 0.5 to 5 parts by weight per 100 parts by weight of filler. The flow additive is preferably used in an amount of about 0.75 to 2.5 parts by weight per 100 parts by weight of hydroxypolysiloxane.

The compositions of the present invention may, and preferably do, contain a modulus lowering agent which may cooperate with the flow additive to enhance the desired flowability. Suitable modulus lowering agents are, for example, those of the formula: RSO ₃ H, where R is optionally halogenated and represents a hydrocarbon residue containing an aliphatic chain of up to 20 carbon atoms, such as those of the formula RSO ₃ H [wherein R represents a monovalent hydrocarbon unit having 6 to 18 carbon atoms or R′C ₆ H ₄ (R ′ is alkyl having 6 to 18 carbon atoms)]
And an alkyl or alkylaryl sulfonic acid represented by and a salt thereof. The preferred acid is dodecylbenzene sulfonic acid (DBSA). This acid is preferably used in an amount of 0.6 to 0.9 parts by weight based on the weight of hydroxypolysiloxane.

The composition of the present invention may contain a liquid plasticizer or extender. For example, non-reactive silicone liquids or gums such as trialkylsilyl endblocked polydiorganosiloxanes or organic diluents can be used. Trialkylsilyl endblocked polydimethylsiloxane is preferred, especially 100-15,000 mm ² / s
It has a viscosity in the range of. These substances are 10
It is effective in reducing the 0% elongation modulus and also contributes to the ability of the composition to adhere to concrete. However, the substance tends to exude from the composition over an extended period of time and is therefore preferably used only if this exudation is acceptable. In such cases, trialkylsilyl endblocked polydimethylsiloxane
It is preferred to use up to about 70 parts by weight, preferably up to 50 parts by weight, per 100 parts by weight of hydroxypolysiloxane.

The compositions of the present invention include other additives often used in silicone sealants such as pigments, antioxidants and adhesion promoters such as hydrolyzable aminosilanes such as γ-amino-propyl-trimethoxysilane, N. −
It can also contain γ-aminoethyl-aminopropyl-triethoxysilane and glycidoxypropyltrimethoxysilane.

The composition according to the invention can consist of one or two parts and the components can be mixed in any desired order. For example, if one prefers to be composed of one part, the moisture-curable composition may either have the mixed filler composition dispersed in the hydroxypolysiloxane, or the filler may be added separately to the hydroxypolysiloxane, Then, it can be prepared by adding a catalyst and a curing agent. While it is necessary to remove excess water from the mixture before adding the hardener, a small excess can be removed during storage by the use of an appropriate amount of hydrolyzable silane. The flow additive has the same effect on the rheology of the system and can be incorporated at any stage of the compounding process. However, in a preferred formulation, the anhydride functionalizing agent is added after the filler is dispersed in the polysiloxane. The pigment and the small amount of additive can be added at a desired stage, but it is preferable to add them as close to the end of the mixing operation as possible. The composition is then packaged in cartridges and aged at room temperature for more than 7 days before use.

The compositions of the present invention have the desired blend of properties suitable for use as a sealant for the filling of building joints, a heat insulating sealant for glass units or glass expansion joints, or a general purpose sealant. Can be blended into. A particular benefit is the ability to formulate compositions that exhibit easy extrusion and thixotropy from the cartridge nozzle to the joint prior to curing and good adhesion to various substrates. In particular, when a modulus-reducing additive such as DBSA is present, it has been found that the composition body prior to cure has similar rheological properties and low modulus to those found to be similar to those obtained from silica-containing compositions. A curable calcium carbonate filled silicone sealant is provided.

[0022]

EXAMPLES In order to clarify the present invention, examples for explaining the present invention will be given below. In addition, "part" is "part by weight" unless otherwise specified. The following tests were performed on the compositions of the examples. The extrusion rate was measured by the weight of the sealant extruded in one minute at 6.2 bar from a standard secom cartridge with a 2 mm diameter nozzle at 25 ° C. Penetration is 3
It measured using the standard penetrometer (PNR10-SVR) with a g needle. Permeability was expressed in mm for 30 seconds. 100
The% elongation modulus, tensile strength, and elongation were measured by pulling a 2 mm sheet sample at a constant rate to failure using a tensiometer and calculating reasonable values. Adhesion to glass was measured by applying sealant beads to the substrate and testing in the following order: cure room temperature 7 days-test-room temperature 2 days water soak-test-50 ° C.
2 days in water-test. The test was performed after initial failure by cutting the sealant / substrate interface joint with a razor blade and then 9
This was done by pulling the beads from the interface at a 0 degree angle. After each test, each bead was ranked based on the type of failure recorded. 0 = initial failure, 1 = boundary failure, 2 = cohesive failure. The final rank is an average value of ranks obtained by three tests.

[0023] Example 1 OH-terminated dimethylpolysiloxane 100 parts of viscosity 50,000 mm ² / s at 25 ° C., a viscosity at 25 ° C. 100 mm ² /
41 parts of trimethylsilyl endblocked dimethylpolysiloxane of s, 106 parts of calcium carbonate having a surface area of 20 m ² / g and 78 parts of calcium carbonate having a surface area of 1 to ² m ² / g (both coated with 3% stearate and 0.4% respectively). 184 parts of the filler mixture contained, 7 parts of methyltrimethoxysilane as a curing agent, 1.8 parts of di- (isopropyl) di (ethylacetoacetate) titanate as a catalyst, N-γ-aminoethyl-α-as an adhesion promoter. A composition useful as a sealant with good adhesion was prepared containing 0.19 parts aminopropyl-trimethoxysilane and 0.9 parts DBSA. A second composition was prepared with the same materials and proportions, to which an acid anhydride functionalized polybutadiene (molecular weight 2160, acid number 70 mg KOH / g, acid anhydride groups 1.3 per chain) was prepared.
5) 1.0 part was added. The first composition had the following physical properties. Extrusion rate (6.2 bar): 320 g / min, permeability: 220 mm / 30 seconds, tensile strength: 1.67 MPa, elongation: 6
88%, 100% modulus: 0.39 MPa, adhesion to glass: 2.00. In contrast to these results, the physical properties of the second composition containing the acid anhydride functionalized polybutadiene are shown to be 230, 140, 1.61, 673 and 0.0, respectively.
40 and 2.00.

Example 2 100 parts of OH-terminated dimethylpolysiloxane having a viscosity of 50,000 mm ² / s at 25 ° C., viscosity at 25 ° C. of 100 mm ² / s
39 parts of trimethylsilyl end-blocked dimethylpolysiloxane of s, 92 parts of calcium carbonate having a surface area of 20 m ² / g, and 69 parts of calcium carbonate having a surface area of 1 to ² m ² / g (both coated with 3% stearate and 0.4%, respectively) 161 parts of a filler mixture containing, 6.25 parts of methyltrimethoxysilane as a curing agent, and di- (isopropyl) as a catalyst.
A composition was prepared containing 1.6 parts di (ethylacetoacetate) titanate, 0.16 parts N-γ-aminoethyl-aminopropyl-trimethoxysilane as an adhesion promoter and 0.75 parts DBSA. A second composition was prepared with the same materials and proportions, to which 0.8 parts of anhydride functionalized polybutadiene was added. The first composition had the following physical properties.
Extrusion rate (6.2 bar): 360 g / min, permeability:
220 mm / 30 seconds, tensile strength: 1.50 MPa, elongation: 510
%, 100% stress: 0.30 MPa, adhesion to glass:
2.00. In contrast to these results, the physical properties of the second composition containing the acid anhydride functionalized polybutadiene were 220, 150, 1.67, 560, 0.30 and 2.00, respectively.

Example 3 100 parts of OH-terminated dimethylpolysiloxane having a viscosity of 50,000 mm ² / s at 25 ° C., viscosity at 25 ° C. of 100 mm ² / s
s of trimethylsilyl endblocked dimethylpolysiloxane 44 parts, surface area 20 m ² / g calcium carbonate 106 parts and surface area 1-2 m ² / g calcium carbonate 78 parts (both stearate 3% and 0.4% respectively). 184 parts of the filler mixture contained, 7 parts of methyltrimethoxysilane as a curing agent, 1.8 parts of di- (isopropyl) di (ethylacetoacetate) titanate as a catalyst, N-γ-aminoethyl-aminopropyl as an adhesion promoter −
Two compositions were prepared containing 0.18 parts trimethoxysilane and 0.6 parts DBSA. The first composition additionally contains 1.0 part of an anhydride-functionalized polybutadiene, a second composition
Of the composition contained 1.5 parts of acid anhydride functionalized polybutadiene. The first composition showed the following physical properties: Extrusion rate (6.2 bar): 220 g / min, permeability: 120 m
m / 30 seconds, tensile strength: 1.59 MPa, elongation: 687%, 10
0% stress: 0.34 MPa, adhesion to glass: 2.00.
In contrast to these results, showing the physical properties of the second composition,
They were 180, 104, 1.81, 752, 0.35 and 2.00, respectively. Examples 1-3 above demonstrate the effect of anhydride functionalized polybutadiene at various concentration levels on the rheology of silicone sealant compositions.

[0026] EXAMPLE 4 OH-terminated dimethylpolysiloxane 100 parts of viscosity 50,000 mm ² / s at 25 ° C., a viscosity at 25 ° C. 100 mm ² /
28 parts of trimethylsilyl end-blocked dimethylpolysiloxane of s, 127 parts of calcium carbonate having a surface area of 20 m ² / g (3% stearate coating), 7-8 parts of methyltris (methylketoxmino) silane, dimethoxymethyl (methylketoxino) 0.4 parts of silane, 2 parts of methoxymethylbis (methylketoximino) silane (these three silanes are used as crosslinkers), γ-aminopropyltrimethoxysilane 2.55 as an adhesion promoter.
Parts and catalyst dibutyltin dilaurate 0.085
A composition containing parts was prepared. A second composition was prepared with the same materials and proportions, to which 2.5 parts of anhydride functionalized polybutadiene was added. The first composition exhibited an extrusion rate of 116 g / min, a permeability of 128 mm / 30 seconds, and the second composition with an anhydride functionalized additive was 72 and 103, respectively.

Example 5 100 parts of OH-terminated dimethylpolysiloxane having a viscosity of 50,000 mm ² / s at 25 ° C., viscosity at 25 ° C. of 100 mm ² / s
20 parts of trimethylsilyl endblocked dimethylpolysiloxane of s, 80 parts of calcium carbonate having a surface area of 20 m ² / g and 45 parts of calcium carbonate having a surface area of 1 to ² m ² / g (both coated with 3% stearate and 0.4% respectively). 125 parts of filler mixture contained, 8 parts of methyltrimethoxysilane as curing agent, 2 parts of di- (isopropyl) di (ethylacetoacetate) titanate as catalyst, N-γ-aminoethyl-aminopropyl-tri The composition containing 0.2 part of methoxysilane had an extrusion rate (6.2 bar) of 400 g / min, a tensile strength of 1.90.
It had MPa, elongation: 464%, 100% stress: 0.71 MPa, and adhesion to glass: 2.00. DBSA 0.65
The second composition additionally containing parts has an extrusion rate (6.
2 bar): 390 g / min, tensile strength: 1.70 MPa, elongation: 600%, 100% stress: 0.42 MPa, adhesion to glass: 2.00. A third composition containing 0.65 parts DBSA and 1 part acid anhydride functionalized polybutadiene had an extrusion rate (6.2 bar) of 330 g / min, a tensile strength of 1.79 MPa, an elongation of 610%, 100%. stress:
It had 0.42 MPa and adhesion to glass: 2.00. Example 5 illustrates that the two additives used in the formulation play a special role.

Example 6 100 parts of OH-terminated dimethylpolysiloxane having a viscosity of 50,000 mm ² / s at 25 ° C., viscosity at 25 ° C. of 100 mm ² / s
39 parts of trimethylsilyl end-blocked dimethylpolysiloxane of s, 92 parts of calcium carbonate having a surface area of 20 m ² / g, and 69 parts of calcium carbonate having a surface area of 1 to ² m ² / g (both coated with 3% stearate and 0.4%, respectively) 161 parts of a filler mixture containing, 7 parts of methyltrimethoxysilane as a curing agent, 1.6 parts of di- (isopropyl) di (ethylacetoacetate) titanate as a catalyst, N-γ-aminoethyl-aminopropyl as an adhesion promoter. Trimethoxysilane 0.16 parts, DBSA 0.75 parts and acid anhydride functionalized polybutadiene, carboxylic acid functionalized polybutadiene (Goodrich: Hycar 200/162), unfunctionalized polybutene (AMOCO: H1500) and Prepare a composition containing 1.0 part of an additive selected from hydroxyl-functionalized polybutadiene (Sartomer R45-HT from Sartomer). did.
The extrusion rate (6.2 bar) of the composition containing the acid anhydride-functionalized polybutadiene is 220 g / min, whereas that of the composition containing the carboxylic acid-functionalized polybutadiene is 280, that of the unfunctionalized polybutene-containing composition. It is 32
0, that of the hydroxyl functionalized polybutadiene composition was 280.

[0029] Example 7 25 OH-terminated dimethylpolysiloxane 100 parts of viscosity 50,000 mm ² / s at ° C., 25 viscosity at ° C. 100 mm ² /
39 parts of trimethylsilyl end-blocked dimethylpolysiloxane of s, 92 parts of calcium carbonate having a surface area of 20 m ² / g, and 69 parts of calcium carbonate having a surface area of 1 to ² m ² / g (both coated with 3% stearate and 0.4%, respectively) 161 parts of a filler mixture containing, 7 parts of methyltrimethoxysilane as a curing agent, 1.6 parts of di- (isopropyl) di (ethylacetoacetate) titanate as a catalyst, N-γ-aminoethyl-aminopropyl as an adhesion promoter. -0.16 parts trimethoxysilane, 0.75 parts DBSA and carboxylic acid functionalized polybutadiene (Goodrich: Hycar 20
0/162) and 2.0 parts of an additive selected from a carboxylic acid functionalized polyester (Huels: Dynacol 8221) was prepared. The extrusion rate (6.2 bar) of the composition containing the carboxylic acid functionalized polybutadiene was 28.
That of the carboxylic acid functionalized polyester-containing composition was 285, compared to 0 g / min.

It is apparent from Examples 6 and 7 above that acid anhydride functional polymers are more effective than those of carboxylic acid functional molecules containing equal amounts of carboxyl groups in the composition. However, hydroxyl functional molecules are undesirable and have a negative effect as sealants. The polymer skeleton has no special function and any skeleton is considered suitable for the purposes of the present invention.

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Claims (9)

[Claims] 1. A product formed by mixing a hydroxypolysiloxane with a silane or siloxane hardener, a finely divided filler, a catalyst that accelerates the cure of the product in the presence of atmospheric moisture, and a flow additive. A curable composition containing a substance, characterized in that the flowable additive contains a polymer having at least one carboxylic acid anhydride group in or on the polymer chain. Sex composition. 2. A composition according to claim 1, wherein the flowable additive is a liquid or a low melting point solid at normal use temperatures. 3. The flow additive is a carboxylic acid anhydride treated molecular weight in the range of 1,000 to 6,000, 1,500 to 2.
A polybutadiene polymer having a viscosity in the range of 0,000 mm ² / s, an acid value in the range of 50 to 200 (mg KOH / g) and an average of 1 to 7 acid anhydride groups per molecule. Composition. 4. The composition according to claim 3, wherein the carboxylic acid anhydride is maleic anhydride. 5. The composition according to claim 1, wherein the filler is precipitated and / or ground calcium carbonate. 6. The filler is hydroxypolysiloxane 1
It is present in the range of 150 to 250 parts by weight per 00 parts by weight, and mainly consists of (i) particles of calcium carbonate having a surface area of 20 m ² / g and (ii) particles having a surface area of 1 to ² m ² / g. The composition according to any one of claims 1 to 5, which contains a mixture with calcium carbonate and has a ratio of (i) to 1 to 3 parts by weight with respect to (ii). 7. The product comprises the component and the general formula: RS.
O ₃ H represents a monovalent hydrocarbon residue having 6 to 18 carbon atoms or R′C ₆ H ₄ (R ′ is an alkyl group having 6 to 18 carbon atoms). ] The composition of any one of claims 1 to 6, which is formed by mixing the alkyl or arylalkyl sulfonic acid. 8. The hydroxypolysiloxane has the general formula:
HO (R ₂ SiO) _x H (wherein each R represents a monovalent hydrocarbon residue having up to 12 carbon atoms, x is a polymer of 5
The composition of any one of claims 1 to 7 0～500,000Mm a dihydroxy polysiloxane represented by integers which) as having a viscosity in the range of ² / s. 9. The composition according to claim 1, wherein the curing agent is methyltrimethoxysilane.